The invention relates to the field of equipment for automatic drink dispensing on request. More specifically, the invention relates to devices intended for use in catering facilities of airplanes, trains, other means of transport, offices or other installations where space for such dispensers is limited.
Currently, there is no drink dispenser that uses soluble powders for the preparation of drinks, such as those based on coffee or the like, in service on airlines. In general, the systems for preparation of coffee for such applications all employ the principle of extraction of ground roast coffee. The time necessary for the extraction renders the principle impractical and inflexible for the preparation of combinations or mixtures such as coffee with milk, cappuccino or the like. Since manual preparation is necessary, such systems cannot be installed in a satisfactory manner as self-service systems for passengers.
On the other hand, drink dispensers using powder-based products do exist in public places. These dispensers are in general devices of fairly large capacity. Such devices comprise containers for powder storage, hoppers downstream of the containers equipped with metering devices, and mixing bowls downstream of the hoppers for receiving the powder, mixing it with a quantity of water and then effecting the dispensing by gravity through dispensing tubes.
In these known drink dispensers, the powder is ejected from the metering device into the mixing bowl by means of a metering screw through an opening zone of the hopper. The metered quantity depends on the number of revolutions of the metering screw. When this principle is applied to dispensers of small dimensions, problems of consistency in the quantity of powder metered and problems of fouling of the mixing bowl and the powder delivery ducts are observed. These problems are due, it seems, to the fact that a little powder always remains at the edge of the opening zone after the metering means has been stopped. At least some of this powder tends to fall into the bowl between preparation cycles, which fouls the bowl, forming poorly soluble pieces or lumps. Some of the powder also tends to agglomerate in the region of the opening of the metering device, forming burr-like encrustations which are made moist and sticky by the steam originating from the mixing bowl. These problems are exacerbated when very hygroscopic powders such as milk powder are used. Regular cleaning of the device is thus essential in order to avoid contamination.
Another problem encountered stems from the production of steam in the downstream part of the dispenser, in particular in the mixing bowl where the water is mixed with the metered quantity of powder. This steam tends to find its way back into the metering device and to moisten the powder located in the hopper and in the storage part. The result is a deterioration in the quantity and the fluidity of the powder, the latter of which can lead to blockage.
Accordingly, there is a need to solve these problems by providing a metering device which can be used in a drink dispensing device, in particular, although not exclusively, for application to a compact dispenser intended for fitting out airliners or other means of transport, and also possibly for offices, cafeterias or restaurants. The present invention satisfies this need.
There is also a need to propose a practical and clean way of refilling powder in a compact dispenser in which the manual operation is maintained as low as possible and in which the refilling operation is accurate and does not mess up the dispensing area.
The present invention relates to a device for metering a powder-based food product comprising a hopper for storage of a food or beverage powder, a feed zone that includes a basic portion having an opening for allowing a metered quantity of powder to fall, a metering device located in the hopper for conveying powder from the hopper to the feed device, a sealing element arranged with the basic portion to provide sealing of the opening of the basic portion, and an operating mechanism for positioning the sealing element in a sealing position when the metering device is not operating.
The sealing element is movable between the sealing position, where the powder cannot fall into the feed zone, and an inoperative position, where powder can fall freely into the feed zone, and wherein the operating mechanism is operatively associated with the sealing element to move the sealing element between the sealing and inoperative positions. Such a device therefore makes it possible to solve the problems associated with the powder falling into the mixing bowl outside the drink preparation cycle and thus makes it possible to avoid the problems due to fouling of the mixing bowl(s) and of fouling or blocking of the dispensing tube(s).
The basic portion comprises a tube that has an opening for allowing powder to fall into the feed zone, and the sealing element is arranged coaxially in relation to the basic portion in order to allow sealing of the basic portion tube opening by rotation of the sealing element around the basic portion. The sealing element is in the form of a tube having open and closed portions, wherein, in the inoperative position, the opening of the sealing element is located adjacent the opening of the basic portion so that powder can fall into the feed zone. Such an arrangement has the advantage of eliminating, by the scraping action of the sealing element, the burr-like powder encrustations that can agglomerate on the edges of the opening. The opening therefore remains perfectly clean after each metering cycle.
According to a preferred aspect, the sealing element itself is also a portion of tube having a slot, with the sealing element being displaceable by sliding in rotation around the basic portion between an open position, in which the slot of the sealing element is at least in part coincident with the opening, and a closed position, in which the slot of the sealing element is displaced completely beyond the area of the opening. In this way, the agglomeration of powder on the edges of the opening is avoided. Furthermore, the sealing element, which seals the opening completely, serves as a steam screen, preventing the powder located in the hopper from absorbing the moisture coming from the steam in the bowl.
The operating mechanism of the sealing element comprises at least one drive means such as an electric motor. Given the fact that the invention relates more specifically to a device intended to fit into a confined space, it is advantageous if the movement of the sealing element is brought about by a drive means located at the rear of the hopper by means of a transmission system. This system includes at least one transmission rod and at least one gear mechanism connected to the rod and the sealing element. The advantages of providing the operating means at the rear of the hopper include the possibility of rendering at least a part of the metering device easily removable and capable of being plugged into the operating means, while keeping the latter permanently connected to the electric circuit of the machine.
The device according to the invention furthermore comprises a control system. The control system carries out a metering cycle that comprises the steps of
(a) actuation of the operating mechanism to move the sealing element from the sealing position to the inoperative position to an open position and deactuation of the operating mechanism when the sealing element is in the inoperative position,
(b) actuation of the metering device to start powder metering,
(c) deactuation of the metering device to stop powder metering, and
(d) reactuation of the operating means to move the sealing element from the inoperative position to the sealing position and deactuation of the operating mechanism when the sealing element is in the sealing position.
The steps (a) to (d) may be carried out in this order or in a different order. In an embodiment, the steps (a) and (b) may be performed simultaneously or (b) be performed slightly before step (a). In another embodiment, the steps (c) and (d) may be also preformed simultaneously or step (d) slightly before step (c).
The invention also relates to a dispensing device allowing the preparation of drinks according to a choice of combinations from at least two sources of powder and having the special feature of being capable of fitting in a compact space such as in the cupboard of an airliner catering compartment or the like. To this end, the drink device according to the invention comprises at least two hoppers for the storage of two different food or beverage-forming powders which can be selected either individually or as a mixture, with each hopper of a pair of hoppers having an asymmetric shape, a side wall that is positioned adjacent the side wall of the other hopper in the pair, and a metering device for allowing the powder to be conveyed to a feed zone; and a common mixing receptacle positioned beneath the hoppers for receiving powder originating from either hopper. The metering device of each hopper of the pair of hoppers is positioned near the side wall that is positioned adjacent to the other hopper, with the two hoppers positioned in relation to a longitudinal median plane of each hopper so as to form a close configuration relative to one another with the feed zones in close proximity to reduce the space requirements for the mixing receptacle.
The two hoppers in the pair are each configured to be a mirror image of the other on either side of a mirror plane that passes between the hoppers along and between the adjacent side walls. Such a configuration has the advantage of making it possible to have a compact apparatus that is nevertheless capable of preparing a large number of drinks from a multiple choice such as, for example, the preparation of hot drinks based on soluble coffee and/or milk.
According to another advantageous aspect of the invention, the device for dispensing drinks on request comprises a housing and at least one hopper in said housing that includes at least one guide member and is adapted to receive a powder refill element, and a housing located above the hopper, wherein the housing and guide member(s) are arranged to allow insertion of the refill element in a primary direction wherein the housing has a free volume capable of receiving the refill element onto the hopper whereby the refill element occupies the free volume to form an extension of the hopper storage. Preferably, the housing has a front panel and the insertion of the refill element is carried out by opening the front panel and inserting the refill element in an essentially horizontal direction. Such a supply device has the advantage of facilitating the powder supply. The supply can therefore be effected from the front of the machine simply by opening the front panel of the device. Such a system has an advantage in relation to a container-filling supply system which necessitates raising the top panel of the machine or at the very least the withdrawal of the container to carry out the refilling. The risks of dropping the powder outside the storage container are therefore reduced.
The device also may include guide means in the form of side walls that form a trough in an inverted configuration to receive and slidingly engage and guide edges of the refill element. The refill element is preferably configured in the form of a trough having a pair of edges, which refill element is inserted in an inverted position with its opening facing in the direction of the hopper, with the trough edges slidingly engaging the guide members for insertion or withdrawal of the refill element. The housing also can include a stop member for each refill element, with the stop member positioning the refill element above the feed zone for supplying the corresponding hopper with powder. In a preferred configuration, two hoppers are provided, mounted in parallel on a drawer that is slidably insertable and removable in the housing.
According to the above-mentioned characteristics, the machine can be produced in a compact manner and can therefore easily be fitted into a catering space while allowing refilling of the device with powder in a rapid manner without any particular difficulty.
The device preferably uses refill elements such as those described in U.S. patent application Ser. No. 09/497,457 filed on Feb. 3, 2000, the content of which is expressly incorporated in the present application by reference thereto.